1. Field of Invention
Embodiments of the present disclosure relate generally to semiconductor devices and methods of manufacturing the same and, more particularly, to interconnection structures in a semiconductor device and methods of manufacturing the same.
2. Related Art
For higher integration of semiconductor devices, widths and spaces of interconnection line patterns in the semiconductor devices need to be continually reduced for increased pattern density of the semiconductor devices. This would worsen the problems related to parasitic capacitance between the adjacent interconnection line patterns and electrical resistance of the interconnection line patterns.
Recently, high performance semiconductor memory devices such as fast dynamic random access memory (DRAM) devices and/or fast NAND-type flash memory devices are quite common in the semiconductor industry. In order to allow high performance semiconductor memory devices, RC delay of the interconnection line patterns constituting the semiconductor memory devices should be reduced. For example, a copper layer having a relatively low electrical resistance has been widely employed to form the interconnection lines such as bit lines of high performance semiconductor memory devices. In addition, various low-k dielectric layers have been used for insulation disposed between the adjacent interconnection lines.
When large and excessive current flows through an interconnection line such as a metal line, an electro-migration phenomenon or a stress-migration phenomenon may occur due to electrical or mechanical stress. The electro-migration phenomenon and/or the stress-migration phenomenon may require a bridge between the adjacent interconnection lines. For example, when the interconnection lines are formed of a copper layer, and a low-k dielectric layer is formed between the adjacent copper lines, it may be difficult to suppress the migration of the copper atoms in the copper lines with the low-k dielectric layer. Thus, a copper bridge may need to be formed between the adjacent copper lines. Otherwise without this bridge or some other equivalent, the copper atoms in the copper lines may migrate to contaminate the semiconductor device and degrade the reliability of the semiconductor device.
A barrier layer has been widely used to suppress the migration of the metal atoms in the metal lines. For example, a metal nitride layer may be used as a copper barrier layer surrounding the copper lines. Further, a nitride layer or a carbide layer may be used as a capping layer formed on top surfaces of the copper lines to suppress the electro-migration phenomenon.